U.S. patent number 8,036,823 [Application Number 12/090,521] was granted by the patent office on 2011-10-11 for navigation system.
This patent grant is currently assigned to Panasonic Corporation. Invention is credited to Takashi Akita, Takuya Hirai, Tsuyoshi Kindo, Takahiro Kudoh.
United States Patent |
8,036,823 |
Akita , et al. |
October 11, 2011 |
Navigation system
Abstract
A navigation system generating a display which enables an
intuitive and instant grasp of a distance to a guide point (such as
a guide target intersection) is provided. The navigation system
displays an object on a route between the vicinity of a vehicle
position and the guide point, and includes a object display control
section which calculates a distance from an arbitrary point on the
route between the vehicle position and the guide point to the guide
point, and sets a mode for displaying the object in accordance with
the distance from the arbitrary position on the route to the guide
point. The object display control section sets, for example, a
display color, a pattern, or a shape of the object in accordance
with the distance from the arbitrary point on the route to the
guide point.
Inventors: |
Akita; Takashi (Hyogo,
JP), Kudoh; Takahiro (Kyoto, JP), Kindo;
Tsuyoshi (Osaka, JP), Hirai; Takuya (Osaka,
JP) |
Assignee: |
Panasonic Corporation (Osaka,
JP)
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Family
ID: |
37967596 |
Appl.
No.: |
12/090,521 |
Filed: |
October 17, 2006 |
PCT
Filed: |
October 17, 2006 |
PCT No.: |
PCT/JP2006/320669 |
371(c)(1),(2),(4) Date: |
April 17, 2008 |
PCT
Pub. No.: |
WO2007/049483 |
PCT
Pub. Date: |
May 03, 2007 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20100153000 A1 |
Jun 17, 2010 |
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Foreign Application Priority Data
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Oct 26, 2005 [JP] |
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2005-310771 |
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Current U.S.
Class: |
701/429;
715/764 |
Current CPC
Class: |
G01C
21/3632 (20130101); G08G 1/0969 (20130101); G01C
21/3635 (20130101) |
Current International
Class: |
G01C
21/00 (20060101) |
Field of
Search: |
;701/201,211,208,200,210,209,207 ;348/47
;340/995.19,995.16,901 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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44 12 859 |
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Nov 1994 |
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DE |
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100 39 687 |
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Feb 2000 |
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DE |
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1 445 583 |
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Aug 2004 |
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EP |
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06-147909 |
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May 1994 |
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JP |
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08-190696 |
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Jul 1996 |
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JP |
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09-145389 |
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Jun 1997 |
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JP |
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409243389 |
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Sep 1997 |
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JP |
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2001-074480 |
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Mar 2001 |
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JP |
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2001-074486 |
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Mar 2001 |
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JP |
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2001-074487 |
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Mar 2001 |
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JP |
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2005-214857 |
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Aug 2005 |
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JP |
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92/00568 |
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Jan 1992 |
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WO |
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2004/099718 |
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Nov 2004 |
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WO |
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Other References
International Search Report mailed Jan. 16, 2007 for International
Application No. PCT/JP2006/320669. cited by other .
Informal Comments submitted for International Application No.
PCT/JP2006/320699 filed on Oct. 17, 2006. cited by other .
European Search Report issued Jul. 23, 2010 in corresponding
European Application No. 06811915.5. cited by other.
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Primary Examiner: Black; Thomas
Assistant Examiner: Marc-Coleman; Marthe
Attorney, Agent or Firm: Wenderoth, Lind & Ponack,
L.L.P.
Claims
The invention claimed is:
1. A navigation system for displaying a guide object on a route
between a vehicle position and a guide point, comprising an object
display control section for (i) calculating a distance from the
guide object at an arbitrary position on the route to the guide
point, the arbitrary position on the route being different than the
vehicle position on the route, and (ii) setting a mode for
displaying the guide object in accordance with the calculated
distance; and a photographed image obtaining section for obtaining
a photographed image of a view ahead of the vehicle, wherein
information on how a halfway point to the guide point is distanced
from the guide point is displayed based on the mode for displaying
the guide object set by the object control section, wherein the
guide object is located on a route image showing an image of the
route between the vehicle position and the guide point, and wherein
the route image is the photographed image obtained by the
photographed image obtaining section.
2. The navigation system according to claim 1, wherein the object
display control section sets a display color of the guide object in
accordance with the calculated distance from the arbitrary position
on the route to the guide point.
3. The navigation system according to claim 2, wherein the object
display control section sets the display color of the guide object
so as to be changed in a gradual manner in accordance with the
calculated distance from the arbitrary position on the route to the
guide point.
4. The navigation system according to claim 1, wherein the object
display control section sets a pattern on the guide object in
accordance with the calculated distance from the arbitrary position
on the route to the guide point.
5. The navigation system according to claim 4, wherein the object
display control section sets the pattern on the guide object such
that a density of the pattern becomes higher at a portion of the
guide object closer to the guide point.
6. The navigation system according to claim 1, wherein the object
display control section sets a shape of the guide object in
accordance with the calculated distance from the arbitrary position
on the route to the guide point.
7. The navigation system according to claim 6, wherein the object
display control section displays a plurality of guide objects, and
wherein the object display control section displays the plurality
of guide objects such that the closer to the guide point a guide
object, from among the plurality of guide objects, is located, the
smaller a size of the guide object becomes.
8. The navigation system according to claim 1, wherein the object
display control section overlays the guide object on the
photographed image.
9. The navigation system according to claim 8, wherein the object
display control section displays the guide object
semi-transparently.
10. The navigation system according to claim 1, further comprising:
a map database for storing a map image; a guide mode switching
section for displaying the map image that is stored in the map
database if a distance between the vehicle position and the guide
point is greater than a predetermined distance, and displaying the
photographed image if the distance between the vehicle position and
the guide point is less than the predetermined distance.
11. The navigation system of claim 1, further comprising: a display
section, wherein the display section displays the guide object in
such a manner as to overlay the guide object on the vehicle
position and a position ahead of the vehicle position on the
photographed image.
12. A navigation system for displaying a guide object on a route
between a vehicle position and a guide point, comprising an object
display control section for (i) calculating a distance from the
guide object at an arbitrary point on the route to the guide point,
the arbitrary position on the route being different than the
vehicle position on the route, and (ii) setting a mode for
displaying the guide object in accordance with the calculated
distance; and a photographed image obtaining section for obtaining
a photographed image of a view ahead of the vehicle, wherein the
object display control section sets a display color of the guide
object in accordance with the calculated distance, wherein the
object display control section sets the display color of the guide
object so as to be changed in a gradual manner in accordance with
the calculated distance, wherein information on how a halfway point
to the guide point is distanced from the guide point is displayed
based on the mode for displaying the guide object set by the object
control section, wherein the guide object is located on a route
image showing an image of the route between the vehicle position
and the guide point, and wherein the route image is the
photographed image obtained by the photographed image obtaining
section.
13. The navigation system according to claim 12, wherein the object
display control section overlays the guide object on the
photographed image.
14. A navigation system for displaying a guide object on a route
between a vehicle position and a guide point, comprising an object
display control section for (i) calculating a distance from the
guide object at an arbitrary position on the route to the guide
point, the arbitrary position on the route being different than the
vehicle position on the route, and (ii) setting a mode for
displaying the guide object in accordance with the calculated
distance; and a photographed image obtaining section for obtaining
a photographed image of a view ahead of a vehicle, wherein the
object display control section sets a pattern on the guide object
in accordance with the calculated distance, wherein the object
display control section sets the pattern on the guide object such
that a density of the pattern becomes higher at a portion of the
guide object closer to the guide point, wherein information on how
a halfway point to the guide point is distanced from the guide
point is displayed based on the mode for displaying the guide
object set by the object control section, wherein the guide object
is located on a route image showing an image of the route between
the vehicle position and the guide point, and wherein the route
image is the photographed image obtained by the photographed image
obtaining section.
15. The navigation system according to claim 14, wherein the object
display control section overlays the guide object on the
photographed image.
16. A navigation system for displaying a guide object on a route
between a vehicle position and a guide point, comprising an object
display control section for (i) calculating a distance from the
guide object at an arbitrary position on the route to the guide
point, the arbitrary position on the route being different than the
vehicle position on the route, and (ii) setting a mode for
displaying the guide object in accordance with the calculated
distance; and a photographed image obtaining section for obtaining
a photographed image of a view ahead of a vehicle, wherein the
object display control section sets a shape of the guide object in
accordance with the calculated distance, wherein the object display
control section displays a plurality of sub-objects of the guide
object on the route between the vehicle position and the guide
point, the plurality of sub-objects forming the guide object,
wherein the object display control section displays the plurality
of sub-objects of the guide object such that the closer to the
guide point a sub-object of the guide object, among the plurality
of sub-objects of the guide object, is located, the smaller a size
of the sub-object of the guide object becomes, wherein information
on how a halfway point to the guide point is distanced from the
guide point is displayed based on the mode for displaying the guide
object set by the object control section, wherein the guide object
is located on a route image showing an image of the route between
the vehicle position and the guide point, and wherein the route
image is the photographed image obtained by the photographed image
obtaining section.
17. The navigation system according to claim 16, wherein the object
display control section overlays the guide object on the
photographed image.
Description
TECHNICAL FIELD
The present invention relates to a navigation system, and more
specifically relates to a navigation system generating a display
which enables an intuitive and instant recognition of a distance to
a guide point.
BACKGROUND ART
In recent years, a navigation system has become widely available
which displays a map of an area surrounding a vehicle position,
calculates a route from the vehicle position to a destination, and
performs a route guide in accordance with the calculated route. In
the navigation system, a guide route is displayed on a map image so
as to be distinguishable from other roads (by changing a color
thereof, or by making a line of the route thick, for example).
Alternatively, when the vehicle reaches a location at a
predetermined distance from an approaching intersection on the
guide route, a guide map of the intersection is displayed on the
map image (for example, as an enlarged map of the intersection).
Accordingly, a driver can understand a road to be traveled or a
direction to proceed at the intersection.
However, during driving, it is difficult for the driver to
understand interrelation between the vehicle position displayed on
the map and an actual vehicle position, and thus there has been
posed a problem in that the driver makes a turn before the guide
target intersection and a problem in that the driver passes through
the intersection. Therefore, in order to show the driver a distance
to the guide target intersection, a technique has been disclosed in
which, in accordance with a distance between the vehicle position
and the guide target intersection, a color of an arrow, which shows
a direction to proceed at the intersection, is changed (Patent
document 1).
Patent document 1: Japanese Laid-Open Patent Publication No.
6-147909
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
However, according to the conventional technique disclosed in
above-described Patent document 1, in accordance with the distance
between the vehicle position and the guide target intersection, the
color of the arrow is changed (for example, when the vehicle
reaches a location 300 m before the intersection, the color of the
arrow is changed to red, when the vehicle reaches a location 200 m
before the intersection, the color of the arrow is changed to
yellow, and when the vehicle reaches a location 100 m before the
intersection, the color of the arrow is changed to blue).
Accordingly, only a distance between the two points, i.e., the
vehicle position and the guide target intersection, is shown, and
the driver cannot obtain information on a distance between the
guide target intersection and a halfway point between the vehicle
position and the guide target intersection. Therefore, during
driving at a location relatively far from the intersection (for
example, at a location 300 m before the intersection), the driver
cannot obtain a measure indicative of a distance between the
location and a location proximity to the intersection (for example,
a location 100 m before the intersection), and thus a problem is
posed in that it is difficult to understand the distance to the
intersection and also difficult to intuitively grasp when to
prepare for making a turn.
Particularly in the case where the guide is performed by using a
display which is close to an actual scene viewed by the driver, for
example, by placing an arrow on a route in a photographed image, it
tends to be difficult to understand the distance from a display in
which the arrow is wholly drawn in a single color as disclosed in
the conventional technique, and be also difficult to specify the
intersection at which a turn is to be made.
Further, in the conventional technique, the driver can only confirm
a distance between the two points, i.e., the vehicle position and
the guide target intersection, at a moment when the driver views a
screen. Therefore, the driver cannot grasp positional information
on a location 100 m before the intersection when the driver travels
at a location further before the location (e.g., a location 300 m
before the intersection). The driver can finally grasp the
positional information on the location 100 m before the
intersection when the vehicle actually reaches the position.
Accordingly, in order to confirm a distance to the guide target
intersection, the driver needs to check constantly a change in the
color of the arrow, and consequently, the driver needs to focus on
the screen or view the screen frequently.
Therefore, an object of the present invention is to provide a
navigation system generating a display which enables an intuitive
and instant recognition of a distance to a guide point.
Solution to the Problems
To achieve the above-described object, the present invention has
the following aspects. A navigation system according to the present
invention displays an object on a route between a vehicle position
and a guide point, and comprises an object display control section
for calculating a distance from an arbitrary position on the route
to the guide point, the route being between the vehicle position
and the guide point, and for setting a mode for displaying the
object in accordance with the calculated distance. The guide point
is a target point to be guided by the navigation system, and is
typified by a guide target intersection (an intersection at which
the a vehicle making a turn to the right or the left), a
destination, and a stopover. The arbitrary position on the route
includes the guide point and the vehicle position.
As an example, the object display control section sets a display
color of the object in accordance with the distance from the
arbitrary position on the route to the guide point. Accordingly,
information on a distance between a halfway point to the guide
point and the guide point is also displayed. Therefore, the driver
can obtain a measure to grasp a sense of distance, and becomes able
to grasp the distance to the guide point intuitively and instantly.
Consequently, the driver no longer needs to focus on a screen
constantly, and thus is able to drive safely. Further, since the
display color of the object is changed in accordance with the
distance from the arbitrary point on the route to the guide point,
the driver can grasp the distance to the guide point intuitively
even though the driver does not clearly understand the relation
between the display color and the distance.
Preferably, the object display control section sets the display
color of the object so as to be changed in a gradual manner in
accordance with the distance from the arbitrary position on the
route to the guide point. Accordingly, the display color is changed
continuously in accordance with the distance to the guide point,
and at a location closer to the intersection, the display color
becomes closer to a color assigned to the guide point. Therefore,
the distance to the guide point can be grasped more
intuitively.
Further, in the case where the display color is changed at
predetermined distance interval in accordance with the distance to
the guide point (for example, displayed in red at a distance
interval between the guide target intersection to a location 100 m
before the intersection, and displayed in blue at a distance
interval ranging from 100 m to 200 m before the intersection), the
whole of an arrow is displayed in a single display color in the
vicinity of the intersection (100 m or less before the
intersection, in this case). However, the display color is set so
as to be changed in a gradual manner, whereby the display color of
the arrow at an arbitrary position can be changed in accordance
with the distance from the arbitrary position on the route to the
guide point, and thus the driver can constantly grasp the distance
to the guide point.
The object display control section may set a pattern on the object
in accordance with the distance from the arbitrary position on the
route to the guide point. Preferably, the pattern on the object is
set such that a density of the pattern becomes higher at a portion
of the object closer to the guide point. Accordingly, an effect can
be obtained in which the density of the pattern on the object
becomes higher in the vicinity of the vehicle position as the
vehicle gradually comes closer to the guide point. Accordingly, the
driver can grasp the distance to the guide point intuitively.
The object display control section may set a shape of the object in
accordance with the distance from the arbitrary position on the
route to the guide point. Preferably, the object display control
section displays a plurality of the objects, and displays such that
the closer to the guide point an object, among the objects, is
located, the smaller a size of the object becomes. Accordingly, an
effect can be obtained in which the size of the object in the
vicinity of the vehicle position becomes gradually smaller as the
vehicle comes closer to the guide point, and the driver can grasp
the distance to the guide point intuitively.
The object display control section may overlay the object on the
photographed image. Accordingly, it is possible to grasp the
distance to the guide point intuitively on the photographed image
on which an actual scene ahead of the vehicle is reflected as it
is, and also possible to easily grasp the distance to the guide
point on the actual scene lying ahead of the windshield.
Preferably, the object overlaid on the photographed image is
processed through transparency processing so as to be seen
transparently. Accordingly, it is possible to avoid a situation in
which the scene ahead of the vehicle (such as vehicles traveling
ahead) is covered and cannot be seen.
Effect of the Invention
In the navigation system according to the present invention, as is
clear from the above-described solution to solve the problems, it
is possible to generate a display which enables an intuitive and
instant grasp of a distance to a guide point. Accordingly, the
driver does not need to constantly focus on a screen, and is able
to drive safely.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing a configuration of a navigation system
according to the present invention.
FIG. 2 is a flowchart showing an operation of the navigation system
according to the present invention.
FIG. 3 shows a flowchart showing an operation of a photographed
image display mode.
FIG. 4 is a diagram showing a setting method of a camera view space
in a three-dimensional map space.
FIG. 5 is a diagram showing portions of roads detected through road
detection processing.
FIG. 6 is a diagram showing a location of a guide object in a
three-dimensional map space.
FIG. 7 is a diagram showing a distance setting method in distance
setting processing.
FIG. 8 is a diagram showing the guide object in the
three-dimensional space in the case where a display color thereof
is changed in a gradual manner in accordance with a distance to the
guide target intersection (in the case where reference colors are
two of red and blue).
FIG. 9 is a diagram showing the guide object displayed on the
display section 5 in the case where the display color thereof is
changed in the gradual manner in accordance with the distance (300
m before the intersection) to the guide target intersection.
FIG. 10 is a diagram showing the guide object displayed on the
display section 5 in the case where the display color thereof is
changed in the gradual manner in accordance with the distance (150
m before the intersection) to the guide target intersection.
FIG. 11 is a diagram showing the guide object displayed on the
display section 5 in the case where the display color thereof is
changed in the gradual manner in accordance with the distance to
the guide target intersection (in the case where reference colors
are three of red, yellow and blue).
FIG. 12 is a diagram showing the guide object displayed on the
display section 5 in the case where the display color thereof is
changed at a predetermined distance interval in accordance with the
distance to the guide target intersection.
FIG. 13 is a diagram showing the guide object in the case where a
density of the display color is changed in accordance with the
distance to the guide target intersection.
FIG. 14 is a diagram showing the guide object displayed on the
display section 5 in the case where a pattern on the guide object
is changed in accordance with the distance to the guide target
intersection.
FIG. 15 is a diagram showing the guide object displayed on the
display section 5 in the case where a shape of the guide object is
changed in accordance with the distance to the guide target
intersection.
DESCRIPTION OF THE REFERENCE CHARACTERS
1 position determining section 2 photographed image obtaining
section 3 map DB 4 input section 5 display section 6 control
section 7 route searching section 8 guide mode switching section 9
object display control section
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a navigation system according to the present invention
will be described with reference to diagrams. In each of the
diagrams, component parts which are not related to the present
invention are omitted. FIG. 1 is a configuration diagram showing a
general configuration of the navigation system according to the
present invention. The navigation system is composed of a position
determining section 1, a photographed image obtaining section 2, a
map DB3, an input section 4, a display section 5 and a control
section 6.
The position determining section 1 is a position determining sensor
for obtaining information on a vehicle position, and is typified by
a GPS (Global Positioning System) and a gyroscope fixed to a
vehicle. The photographed image obtaining section 2 is a camera for
picking up an image forward of the vehicle. The image to be picked
up may be either of a still image or a moving image.
The map DB3 is means for storing map information necessary for
route guiding and searching, and is, for example, realized by an
HDD and a DVD.
The input section 4 is means for inputting, to the navigation
system, information relating to a destination, and is composed of a
remote control, a touch panel, a microphone for inputting sounds,
and the like. The display section 5 displays a map image and a
photographed image, and is typified by a LCD display, for
example.
The control section 6 is, for example, a CPU, and is composed of a
route searching section 7, a guide mode switching section 8 and an
object display control section 9. With reference to the information
relating to the destination inputted by the input section 4, the
vehicle position information obtained by the position determining
section 1, and the map DB3, the route searching section 7 searches
a route to the destination. With reference to the vehicle position
information obtained by the position determining section 1 and a
guide route searched by the route searching section 7, the guide
mode switching section 8 calculates a distance to a guide target
intersection which the vehicle is to pass through subsequently.
When a distance to the guide target intersection is greater than a
predetermined distance (a mode switching distance), a map image is
displayed (a map display mode), whereas when the distance to the
guide target intersection is equal to or less than the
predetermined distance, the photographed image is displayed (a
photographed image display mode).
In the photographed image display mode, the object display control
section 9 overlays a guide object on a position of a road in the
photographed image so as to indicate a guide route. Accordingly,
when the driver approaches the guide target intersection, the
driver can recognize an intersection to be turned at while viewing
the photographed image which reflects an actual scene ahead as it
is. Further, the object display control section 9 calculates a
distance from an arbitrary position on the route between the
vehicle position and the guide target intersection to the guide
target intersection, and sets the display color of the guide object
in accordance with the calculated distance. An operation of the
object display control section 9 will be described later in
detail.
Next, an operation of the navigation system according to the
present invention will be described with reference to the diagrams.
FIG. 2 is a flowchart showing the operation of the navigation
system according to the present invention. When the destination is
set to the navigation system (YES in S1) by using the input section
4, the route searching section 7 searches the route to the
destination in accordance with vehicle position information
obtained by the position determining section 1 (S2). When it is
confirmed that the vehicle is yet to arrive at the destination (NO
in S3), the guide mode switching section 8 searches whether or not
a guide target intersection exists on the route between the vehicle
position and the destination (S4). When the guide target
intersection does not exist on the route between the vehicle
position and the destination (NO in S4), a guide is performed in
the map display mode in which the guide object is overlaid on the
guide route in the map (S7). On the other hand, when the guide
target intersection exists on the route between the vehicle
position and the destination (YES in S4), a distance between the
vehicle position and the guide target intersection which the
vehicle is subsequently passes through is calculated (S5).
Thereafter, the distance between the vehicle position and the guide
target intersection is calculated on a regular basis.
Next, the guide mode switching section 8 determines whether the
distance between the vehicle position and the guide target
intersection is greater or lower than a guide mode switching
distance (for example, a distance of 300 m to the guide target
intersection) (S6). When the distance to the guide target
intersection is greater than the guide mode switching distance (NO
in S6), a guide is performed in the map display mode (S7). On the
other hand, when the distance to the guide target intersection is
equal to or lower than the guide mode switching distance (YES in
S6), a guide is switched to the photographed image display mode in
which the photographed image obtained by the photographed image
obtaining section 2 is displayed, and the guide object is overlaid
on the photographed image (S8). A guide method in the photographed
image display mode will be described later in detail. When the
guide mode switching section 8 determines that the vehicle has
passed through the guide target intersection (YES in S9), and the
guide mode switching section 8 again determines in which mode the
guide is to be performed (S4 to S6). When a guide target
intersection does not exist on the route from the vehicle position
to the destination, or when the distance between the vehicle
position and the guide target intersection is greater than the
guide mode switching distance, the guide mode is switched to the
map display mode. On the other hand, when the distance between the
vehicle position and the guide target intersection is equal to or
lower than the guide mode switching distance, the photographed
image display mode is continuously applied. The route guide is
performed until the vehicle arrives at the destination (YES in
S3).
Next, an operation in the photographed image display mode will be
described with reference to a flowchart shown in FIG. 3. Based on a
three-dimensional map stored in the map DB3, and parameters to
determine an imaging direction and an imaging range of the
photographed image obtaining section 2, the parameters including a
camera position, a camera angle (a horizontal angle and an
elevation angle), a focal length and an image size, the object
display control section 9 calculates a camera view space in a
three-dimensional map space (S11). The three-dimensional map is a
map showing positional information based on a latitude, a longitude
and an altitude. The camera view space is calculated based on a
method shown in FIG. 4, for example. In the three-dimensional map
space, a point (point F), which is positioned away from a camera
position (viewpoint) E by a focal length fin a camera angle
direction, is calculated, and a plain surface (a camera screen)
having an x width and a y height, which corresponds to an image
size, is placed at the point so as to be perpendicular to a vector
from the viewpoint E to the point F. A three-dimensional space,
which is created with half-lines connecting between the viewpoint E
and points at four corners of the camera screen, is then
calculated. Although the three-dimensional space logically extends
to infinity, the view space is set at a position which is at an
appropriate distance from the viewpoint E. Instead of the
three-dimensional map, a camera view space in a two-dimensional map
space may be calculated by using the two-dimensional map which is
obtained by eliminating height information from the
three-dimensional map. Further, the parameters for determining the
imaging direction and the imaging range are not limited to those
above mentioned. As long as the imaging direction and the imaging
range can be determined, other parameters such as a view angle may
be used for determination.
The object display control section 9 then performs, in the
three-dimensional map space, road detection processing for
detecting a road existing in the camera view space and a location
thereof (S12). In the road detection processing, overlapping
between the camera view space and a road area is calculated in the
three-dimensional map space. FIG. 5 shows roads detected through
the road detection processing. FIG. 5 is a diagram of the
three-dimensional map space and the camera view space as viewed
from an upper side thereof. As shown in FIG. 5, the roads in the
view space (a portion with slash lines) are detected through the
road detection processing.
In the three-dimensional map space, the object display control
section 9 then locates the guide object at a location on a road,
which corresponds to the guide route searched by the route
searching section 7, among roads detected through the road
detection processing (S13). FIG. 6 shows a location of the guide
object. A shape of the guide object is not limited to an arrow
figure as shown in FIG. 6. For example, a broken line figure which
is obtained by removing a triangle from a front end of the arrow
figure may be applicable.
The object display control section 9 assigns, to respective points
on the guide object, respective distances to the guide target
intersection (distance setting processing S14). Specifically, as
shown in FIG. 7, the guide target intersection is set as an
original point, and the distances from the respective positions to
the guide target intersection are calculated along the route. FIG.
7 shows the guide object at a position 300 m before the
intersection, and distances to the guide target intersection, which
range from 0 to 300 m, are assigned to respective points in between
the vehicle position and the guide target intersection. The
position (original point) of the guide target intersection is not
limited to a location indicated in FIG. 7, but may be any location,
for example, at a central part of a bending position of the arrow
figure. Further, the distances to the guide target intersection may
be assigned to the positions on the guide object on a minimum
necessary basis so as to determine the display mode of the guide
object.
Based on a result of the distance setting processing, the object
display control section 9 then arranges a color of the guide object
in accordance with the distance to the guide target intersection
(color arrangement processing S15). In the color arrangement
processing, as shown in FIG. 8, for example, a red color is
arranged with respect to a position corresponding to the guide
target intersection (the distance to the intersection: 0 m), a blue
color is arranged with respect to a position corresponding to the
vehicle position (the distance to the intersection: 300 m), and
with respect to a section therebetween, a color is changed in a
gradual manner in accordance with the distance to the guide target
intersection. Accordingly, the color is gradually changed from blue
to red, in a range between the vehicle position and the guide
target intersection. As shown in FIG. 8, for example, at an
intermediate position between the vehicle position and the guide
target intersection (a 150 m point to the intersection), a purple
color is arranged, which is a halftone between red and blue. With
respect to a color of a portion of the guide object, the portion
corresponding to a road taken after a turn at the guide target
intersection (a portion indicated by range A in FIG. 8), the red
color may be arranged in the same manner as the original point.
Alternatively, the color may be changed and displayed depending on
whether the turn is made to the right or left.
The object display control section 9 performs projection
transformation (projection processing, S16) of the guide object by
using the camera screen shown in FIG. 4 as a projection plane. The
display section 5 overlays the guide object having undergone the
projection processing on the photographed image obtained by the
photographed image obtaining section 2, and then displays a
resultant thereof on the display screen (S17). The projection
plane, onto which the guide object is projected in the projection
processing, corresponds to the camera screen of the photographed
image obtaining section 2, and thus the guide object is overlaid on
the road (corresponding to the guide route) shown in the
photographed image. When the guide object is overlaid on the
photographed image, a position of the guide object to be overlaid
may be corrected by detecting a location of the road shot by the
camera using a known image recognition technique such as white line
detection and road edge detection. The photographed image mode is
continuously applied until a photographed image display mode end
condition (in which there is no guide target intersection on the
route between the vehicle position and the destination, or in which
the distance between the vehicle position and the guide target
intersection is greater than the guide mode switching distance) is
satisfied (YES in S18).
FIG. 9 is an exemplary display screen displayed on the display
section 5 at a location 300 m before the intersection. The guide
object shown in FIG. 9 is obtained by projecting the guide object
shown in FIG. 8 onto the photographed image. As shown in FIG. 9,
the guide object is drawn in red at a portion thereof in the
vicinity of the guide target intersection, and drawn in blue at a
portion thereof in the vicinity of the vehicle position. As to a
section between the vehicle position and the guide target
intersection, the color to draw the guide object varies from blue
to red in a gradual manner such that a color close to red is
arranged to a portion closer to the guide target intersection.
FIG. 10 a display screen showing a situation in which the vehicle
further travels about 150 m from a state shown in FIG. 9, and
reaches a location 150 m before the intersection. The color of the
guide object is determined based on the distance to the
intersection. Therefore, as shown in FIG. 10, at the portion in the
vicinity of the guide target intersection, the guide object is
drawn in red, in the same manner as in FIG. 9, whereas at the
portion in the vicinity of the vehicle position, the guide object
is drawn in purple which indicates that the location is 150 m
before the intersection. The section between the vehicle position
and the guide target intersection is drawn with a color varying
from purple to red in a gradual manner such that a portion close to
the guide target intersection is drawn in a color close to red.
That is, at the location 150 m before the intersection, only a
range B of the guide object shown in FIG. 8 is drawn.
As above described, the display color of the guide object is set in
accordance with the distance between the arbitrary position on the
route and the guide target intersection, whereby information
indicative of a relative distance between a halfway point to the
guide target intersection and the guide target intersection is also
displayed. Accordingly, the driver is able to obtain a measure to
grasp a sense of distance, and is also able to grasp intuitively
and instantly the distance to the guide target intersection.
Particularly, this effect becomes significant since, in the case
were the display color of the guide object is set to vary in the
gradual manner, as shown in the above described example, the
display color varies continuously in accordance with the distance
to the guide target intersection, and consequently the display
color becomes closer to the color assigned to a portion of the
guide target intersection, the portion being in the vicinity of the
guide target intersection.
Further, the guide object is overlaid on the position on the road
(corresponding to the guide route) in the photographed image,
whereby it is possible to intuitively grasp the distance to the
guide target intersection on the photographed image on which the
actual scene ahead of the vehicle is reflected as it is.
Accordingly, it is possible to easily grasp the distance to the
guide target intersection in the actual scene lying ahead of the
windshield. In this case, an image is displayed by the display
section 5 such that the vehicle travels on the guide object drawn
on the road. In the case of the above-described example, at the
location 300 m before the intersection, a portion of the guide
object drawn in blue lies ahead of the vehicle, and a portion drawn
in red is viewed far ahead. As the vehicle approaches the guide
target intersection, the display changes as if the vehicle travels
on the guide object. In the case of the above-described example, as
the vehicle approaches the guide target intersection, the color of
the guide object in the vicinity of the vehicle becomes closer to
red, and further approaches the portion drawn in red gradually.
According to the display as above described, it is possible to
intuitively grasp the distance to the intersection, and also
possible to instantly grasp the distance to the guide target
intersection regardless of where the vehicle travels.
Preferably, the guide object overlaid on the photographed image is
processed through transparency processing so as to see the
background through the guide object. Accordingly, it is possible to
avoid a situation in which a scene ahead (e.g., vehicles traveling
ahead) of the vehicle is covered by the guide object and cannot be
seen.
In the case of the above-described example, in the color
arrangement processing, only two colors, i.e., the red color
(representing the guide target intersection) and the blue color
(representing the vehicle position) are used as the reference
colors, and to the section therebetween, colors between red and
blue are assigned. However, the colors used as the reference are
not limited to two. For example, as shown in FIG. 11, three colors,
i.e., red, yellow, and blue are used as the reference colors, and
the color of the portion of the guide object in the vicinity of the
vehicle position may be changed from blue to yellow and then to red
in a gradual manner as the vehicle approaches the intersection.
The color set in the color arrangement processing may not
necessarily be displayed in a gradual manner. For example, as shown
in FIG. 12, a distance interval between the guide target
intersection and a position 100 m before the intersection may be
displayed in red, a distance interval ranging 100 to 200 m before
the intersection may be displayed in yellow, and a distance
interval ranging 200 to 300 m before the intersection may be
displayed in blue.
In addition to the case where a color phase is changed as above
described, parameters of the color such as lightness, saturation, a
density and a contrast may be changed. FIG. 13 shows a display
screen in the case where the density of the color is changed. As
shown in FIG. 13, an effect can be obtained in which an area of a
deeper color approaches gradually, as the vehicle approaches the
intersection.
In addition to the color, a pattern of the guide object may be
changed. FIG. 14 shows a display screen in the case where the
pattern of the guide object is changed in accordance with the
distance to the guide target intersection. As shown in FIG. 14, at
a portion closer to the intersection, spacing of a pattern drawn on
the guide object (horizontal lines) is set to become narrower,
whereby an effect can be obtained, in which the density of the
pattern on the object in the vicinity of the vehicle position
becomes higher gradually as the vehicle approaches the guide target
intersection. Accordingly, the driver can intuitively recognize the
distance to the guide target intersection.
Further, a shape of the guide object may be changed. As shown in
FIG. 15, under the condition where a guide display is configured
with a plurality of the guide objects, when the guide objects are
arranged such that the object closer to the intersection is of a
smaller size, the driver can intuitively recognize the distance to
the intersection in the same manner as the case shown in FIG. 14.
Without limiting to the above-described examples, any form may be
applicable as long as the pattern and the shape of the guide object
changes in accordance with the distance to the intersection. The
case where any one of the display color, the pattern and the shape
of the guide object is changed independently, as above described,
may be replaced with a case where the display is performed by using
any combination of these.
In the above-described example, a guide point is described as the
guide target intersection. However, without limiting to this, the
destination, a stopover may be used as the guide point. In this
case, when the vehicle reaches a location 300 m before the
destination, for example, in the same manner as the above-described
case where the guide target intersection is used, the guide is
switched to the photographed image display mode, and the color, the
shape and the pattern of the guide object is changed in accordance
with the distance to the destination, whereby the distance to the
destination is displayed in a manner intuitively and easily
recognizable by the driver.
The photographed image displayed in the photographed image display
mode is obtained from a camera which picks up an image ahead of the
vehicle, but may be replaced with a video picture of the
intersection which is stored in a HDD or obtained through
communication. In the above-described example, a case has been
described where the guide object is overlaid on the photographed
image display screen and the guide is performed. However, the
present invention may be applied to a case where the guide object
is overlaid on the guide route in the map display screen, and a
color, a shape, a pattern of the guide object may be changed in
accordance with the distance to the guide point. In this case, the
driver can obtain the measure to grasp the sense of distance, the
driver can intuitively and instantly grasp the distance to the
guide point. This effect become significant particularly in the
case where the present invention is applied to a guide using a
driver viewpoint map display in which a realistic scene, which is
similar to a scene actually viewed by the driver, is reproduced.
Further, the photographed image and the map image are displayed in
a dual-screen display mode, and the present invention may be
applied to each of the images. In the above-described example, the
camera is fixed to the vehicle, but, without limiting to this, may
be fixed to a mobile unit such as a cellular phone.
While the invention has been described in detail, the foregoing
description is in all aspects illustrative and not restrictive. It
is understood that numerous other modifications and variations can
be devised without departing from the scope of the invention.
INDUSTRIAL APPLICABILITY
The navigation system according to the present invention exerts an
effect of generating a display which enables an intuitive and
instant grasp of the distance to the guide point, and is useful as
a car navigation system installed in a vehicle, a navigation system
for a mobile unit such as a cellular phone, and the like.
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